U.S. patent application number 15/619024 was filed with the patent office on 2017-09-28 for chamber components with polished internal apertures.
The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Vahid Firouzdor, Biraja Prasad Kanungo, David Koonce, Jennifer Y. Sun.
Application Number | 20170274493 15/619024 |
Document ID | / |
Family ID | 54929530 |
Filed Date | 2017-09-28 |
United States Patent
Application |
20170274493 |
Kind Code |
A1 |
Sun; Jennifer Y. ; et
al. |
September 28, 2017 |
CHAMBER COMPONENTS WITH POLISHED INTERNAL APERTURES
Abstract
Disclosed herein are systems and methods for polishing internal
surfaces of apertures in semiconductor processing chamber
components. A method includes providing a ceramic article having at
least one aperture, the ceramic article being a component for a
semiconductor processing chamber. The method further includes
polishing the at least one aperture based on flowing an abrasive
media through the at least one aperture of the ceramic article, the
abrasive media including a polymer base and a plurality of abrasive
particles.
Inventors: |
Sun; Jennifer Y.; (Mountain
View, CA) ; Firouzdor; Vahid; (San Mateo, CA)
; Koonce; David; (Santa Clara, CA) ; Kanungo;
Biraja Prasad; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
|
|
Family ID: |
54929530 |
Appl. No.: |
15/619024 |
Filed: |
June 9, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14318518 |
Jun 27, 2014 |
9687953 |
|
|
15619024 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23B 2226/18 20130101;
B24B 5/40 20130101; B24B 33/02 20130101; B23B 2220/445 20130101;
B23B 35/00 20130101; B24B 31/003 20130101; B24B 31/116 20130101;
B24B 31/006 20130101 |
International
Class: |
B24B 31/00 20060101
B24B031/00; B24B 33/02 20060101 B24B033/02; B24B 31/116 20060101
B24B031/116; B24B 5/40 20060101 B24B005/40 |
Claims
1-14. (canceled)
15. A chamber component comprising: a ceramic body; and a plurality
of polished apertures in the ceramic body, wherein a roughness of
the plurality of polished apertures is less than 32 .mu.in.
16. The chamber component of claim 15, wherein at least one of the
plurality of polished apertures has a first diameter at a first
region and a second diameter at a second region, wherein the second
diameter is less than the first diameter.
17. The chamber component of claim 15, wherein at least one of the
plurality of polished apertures comprises at least one bend within
the chamber component.
18. The chamber component of claim 15, wherein an opening of at
least one of the plurality of apertures has a rounded edge.
19. The chamber component of claim 15, wherein the ceramic body
comprises at least one of Al.sub.2O.sub.3, AlN,
SiO.sub.2,Y.sub.3Al.sub.5O.sub.12, Y.sub.4Al.sub.2O.sub.9,
Y.sub.2O.sub.3, Er.sub.2O.sub.3, Gd.sub.2O.sub.3,
Er.sub.3Al.sub.5O.sub.12, Gd.sub.3Al.sub.5O.sub.12, YF.sub.3,
Nd.sub.2O.sub.3, Er.sub.4Al.sub.2O.sub.9, ErAlO.sub.3,
Gd.sub.4Al.sub.2O.sub.9, GdAlO.sub.3, Nd.sub.3Al.sub.5O.sub.12,
Nd.sub.4Al.sub.2O.sub.9, NdAlO.sub.3, or a ceramic compound
comprising Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3-ZrO.sub.2.
20. The chamber component of claim 15, wherein the chamber
component comprises one of a showerhead gas distribution plate or a
nozzle.
21. The chamber component of claim 15, wherein the chamber
component is a component for a semiconductor processing chamber,
and wherein the chamber component is selected from a group
consisting of a substrate support assembly, an electrostatic chuck,
a gas distribution plate, a nozzle, a showerhead, a flow equalizer,
a cooling base, a gas feeder, a liner kit, and a chamber lid.
22. The chamber component of claim 15, wherein the ceramic body
comprises at least one of Y.sub.3Al.sub.5O.sub.12,
Y.sub.4Al.sub.2O.sub.9, Y.sub.2O.sub.3, Er.sub.2O.sub.3,
Gd.sub.2O.sub.3, Er.sub.3Al.sub.5O.sub.12,
Gd.sub.3Al.sub.5O.sub.12, YF.sub.3, Nd.sub.2O.sub.3,
Er.sub.4Al.sub.2O.sub.9, ErAlO.sub.3, Gd.sub.4Al.sub.2O.sub.9,
GdAlO.sub.3, Nd.sub.3Al.sub.5O.sub.12, Nd.sub.4Al.sub.2O.sub.9,
NdAlO.sub.3, or a ceramic compound comprising
Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3-ZrO.sub.2.
23. The chamber component of claim 15, wherein a diameter of the at
least aperture of the plurality of apertures is between about 0.01
inches and about 0.1 inches.
24. The chamber component of claim 15, wherein the at least one
aperture of the plurality of apertures is polished by flowing an
abrasive media through the at least one aperture, wherein the
abrasive media comprises a polymer base and a plurality of abrasive
particles, and wherein a viscosity of the abrasive media is between
about 150,000 cP and about 750,000 cP.
25. The chamber component of claim 24, wherein flowing the abrasive
media through the at least one aperture comprises periodically
adjusting a flow direction of the abrasive media through the at
least one aperture over a time duration, wherein a length of the
time duration is between about 20 minutes and about 60 minutes.
26. The chamber component of claim 24, wherein the plurality of
abrasive particles comprises at least one of silicon carbide,
diamond, or boron nitride.
27. The chamber component of claim 24, wherein an average size of
each of the plurality of abrasive particles is between 5
micrometers and 100 micrometers.
28. The chamber component of claim 24, wherein the abrasive media
further comprises an oil-based plasticizer.
29. The chamber component of claim 24, wherein at least one
aperture of the plurality of apertures is formed by: drilling with
a drill through the ceramic article to produce the at least one
aperture; and reaming with a reaming device the at least one
aperture with a reaming device to increase a diameter of the at
least one aperture prior to performing the polishing.
30. The chamber component of claim 29, wherein a first grit size of
the drill is courser than a second grit size of the reaming device,
wherein the first grit size of the drill is between about 100 grit
and about 150 grit, and wherein the second grit size of the reaming
device is between about 400 grit and about 800 grit.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 14/318,518, filed Jun. 27, 2014, the disclosure of which
is hereby incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] Embodiments of the present invention relate, in general, to
polishing internal surfaces of apertures in semiconductor
processing chamber components and to chamber components with
polished internal apertures.
BACKGROUND
[0003] In the semiconductor industry, devices are fabricated by a
number of manufacturing processes producing structures of
ever-decreasing size. As the critical dimensions for semiconductor
devices continue to shrink, there is an unyielding need to improve
the cleanliness of the processing environment within a
semiconductor process chamber. Such contamination may be caused, in
part, by chamber components. For example, contamination may be
caused by gas delivery components, such as a showerhead.
[0004] Many bulk ceramic components include small apertures that
allow for process gas flow. These apertures are usually drilled
after performing a sintering process, which often results in rough
internal surface finishes. Such rough interior surfaces serve as
sources of on-wafer defects, since they are directly in contact
with the flow of the process gases. To improve upon on-wafer defect
performance, particulates can be at least partially removed, for
example, from the rough internal apertures by thermal oxidation
processes and by radio frequency (RF) conditioning of the component
after thermal oxidation. However, some components, such as
showerheads, often involve more than 100 hours of RF conditioning
prior to using in a semiconductor process chamber in order to
satisfactorily reduce particles.
SUMMARY
[0005] Embodiments of the present disclosure relate to the
polishing of interior surfaces of apertures in ceramic articles. In
one embodiment, a method includes providing a ceramic article
having at least one aperture, the ceramic article being a component
for a semiconductor processing chamber. The method further includes
polishing the at least one aperture based on flowing an abrasive
media through the at least one aperture of the article. The
abrasive media includes a polymer base and a plurality of abrasive
particles.
[0006] In another embodiment, a system includes a mounting stage, a
clamp, and a pump fluidly coupled to the mounting stage by a
ceramic article disposed between the clamp and mounting stage. An
abrasive media flow path from the mounting stage to the clamp is
defined by an aperture of a ceramic article.
[0007] In another embodiment, a chamber component includes a
ceramic body and a plurality of apertures in the ceramic body. A
roughness of the plurality of apertures is less than 32 .mu.in.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention is illustrated by way of example, and
not by way of limitation, in the figures of the accompanying
drawings in which like references indicate similar elements. It
should be noted that different references to "an" or "one"
embodiment in this disclosure are not necessarily to the same
embodiment, and such references mean at least one.
[0009] FIG. 1 depicts a sectional view of a processing chamber
according to an embodiment;
[0010] FIG. 2 depicts an exemplary architecture of a manufacturing
system according to an embodiment;
[0011] FIG. 3 depicts a sectional view of an abrasive flow system
according to an embodiment;
[0012] FIGS. 4a-4i are micrographs comparing unpolished apertures
to apertures polished according to an embodiment;
[0013] FIG. 5 is a flow diagram illustrating a process for
polishing interior surfaces of apertures in a ceramic article
according to an embodiment and
[0014] FIG. 6 is a flow diagram illustrating a process 500 for
polishing interior surfaces of apertures in a ceramic article
according to an embodiment according to another embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0015] Embodiments of the present invention provide a ceramic
article, such as a chamber component for a processing chamber. The
ceramic article may have a composition of one or more of
Al.sub.2O.sub.3, AlN, SiO.sub.2, Y.sub.3Al.sub.5O.sub.12 (YAG),
Y.sub.4Al.sub.2O.sub.9 (YAM), Y.sub.2O.sub.3, Er.sub.2O.sub.3,
Gd.sub.2O.sub.3, Gd.sub.3Al.sub.5O.sub.12 (GAG), YF.sub.3,
Nd.sub.2O.sub.3, Er.sub.4Al.sub.2O.sub.9, Er.sub.3Al.sub.5O.sub.12
(EAG), ErAlO.sub.3, Gd.sub.4Al.sub.2O.sub.9, GdAlO.sub.3,
Nd.sub.3Al.sub.5O.sub.12, Nd.sub.4Al.sub.2O.sub.9, NdAlO.sub.3, or
a ceramic compound composed of Y.sub.4Al.sub.2O.sub.9 and a
solid-solution of Y.sub.2O.sub.3-ZrO.sub.2. The ceramic article
includes one or more apertures passing through the ceramic article
(e.g., to allow for gas flow through the ceramic article and into a
processing chamber). The apertures may have been formed by drilling
(e.g., acoustic drilling, laser drilling, mechanical drilling,
etc.) into the ceramic article. The apertures may additionally be
reamed following the drilling to increase a diameter of the drilled
aperture.
[0016] To increase the smoothness of the interior surfaces of the
apertures, an abrasive media is introduced into the apertures using
an abrasive flow system. Abrasive flow machining is a surface
finishing process that involves the flowing of a highly viscous
abrasive media through apertures, slots, or other areas which may
be difficult to reach by conventional polishing technologies. The
abrasive media includes a highly viscous polymer base and abrasive
particles such as silicon carbide, diamond, and/or boron nitride
particles. The polishing effect can be varied by adjusting the
viscosity of the media (e.g., changing the type of the polymer
component or the amount of the abrasive loading into the polymer),
a grit and/or type of the abrasive particles, and/or a pressure
used to flow the media inside the apertures.
[0017] The disclosed systems and methods provide improved (e.g.,
smoother) surface finish within small apertures of semiconductor
chamber ceramic articles over traditional articles. The improved
surface finish of the apertures advantageously facilitates
processing of semiconductor wafers by reducing particulates that
result from use of the ceramic article within the semiconductor
processing chamber. The systems and methods described herein
further advantageously reduce process operations (e.g., oxidation
and/or radio frequency conditioning) and/or processing times for
the fabrication of chamber components used in process gas
distribution. Radio frequency (RF) conditioning is the process of
performing one or more operations to season or condition a chamber
component. Moreover, some embodiments of the disclosed methods
utilize drilling followed by reaming to produce apertures. When
drilling and reaming is performed in conjunction with abrasive flow
polishing, defects produced in the drilling/reaming process can be
mitigated. Mitigation of the defects allows for robust and novel
ways of fabricating apertures in ceramic articles.
[0018] FIG. 1 is a sectional view of a semiconductor processing
chamber 100. The processing chamber 100 may be used for processes
in which a corrosive plasma environment is provided. For example,
the processing chamber 100 may be a chamber for a plasma etcher or
plasma etch reactor, a plasma cleaner, and so forth. Examples of
chamber components that may include one or more apertures include,
but are not limited to, a substrate support assembly 148, an
electrostatic chuck (ESC) 150, a gas distribution plate, a nozzle,
a showerhead, a flow equalizer, a cooling base, a gas feeder, and a
chamber lid 104. The apertures, which are described in greater
detail below, may be apertures formed by drilling and/or reaming
the chamber component during fabrication. The chamber component may
be a ceramic article having a compositing of at least one of
Al.sub.2O.sub.3, AlN, SiO.sub.2, Y.sub.3Al.sub.5O.sub.12, Y.sub.4Al
O.sub.12, Y.sub.4Al.sub.2O.sub.9, Er.sub.2O.sub.3, Gd.sub.2O.sub.3,
Gd.sub.3Al.sub.5O.sub.12, YF.sub.3, Nd.sub.2O.sub.3,
Er.sub.4Al.sub.2O.sub.9, Er.sub.3Al.sub.5O.sub.12, ErAlO.sub.3,
Gd.sub.4Al.sub.2O.sub.9, GdAlO.sub.3, Nd.sub.3Al.sub.5O.sub.12,
Nd.sub.4Al.sub.2O.sub.9, NdAlO.sub.3, or a ceramic compound
composed of Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3-ZrO.sub.2.
[0019] In one embodiment, the processing chamber 100 includes a
chamber body 102 and a showerhead 130 that enclose an interior
volume 106. Alternatively, the showerhead 130 may be replaced by a
lid and a nozzle in some embodiments. The chamber body 102 may be
fabricated from aluminum, stainless steel or other suitable
material. The chamber body 102 generally includes sidewalls 108 and
a bottom 110. One or more of the showerhead 130 (or lid and/or
nozzle), sidewalls 108 and/or bottom 110 may include a one or more
apertures.
[0020] An outer liner 116 may be disposed adjacent the sidewalls
108 to protect the chamber body 102. The outer liner 116 may be
fabricated to include one or more apertures. In one embodiment, the
outer liner 116 is fabricated from aluminum oxide.
[0021] An exhaust port 126 may be defined in the chamber body 102,
and may couple the interior volume 106 to a pump system 128. The
pump system 128 may include one or more pumps and throttle valves
utilized to evacuate and regulate the pressure of the interior
volume 106 of the processing chamber 100.
[0022] The showerhead 130 may be supported on the sidewall 108 of
the chamber body 102. The showerhead 130 (or lid) may be opened to
allow access to the interior volume 106 of the processing chamber
100, and may provide a seal for the processing chamber 100 while
closed. A gas panel 158 may be coupled to the processing chamber
100 to provide process and/or cleaning gases to the interior volume
106 through the showerhead 130 or lid and nozzle (e.g., through
apertures of the showerhead or lid and nozzle). Showerhead 130 may
be used for processing chambers used for dielectric etch (etching
of dielectric materials). The showerhead 130 includes a gas
distribution plate (GDP) 133 having multiple gas delivery apertures
132 throughout the GDP 133. The showerhead 130 may include the GDP
133 bonded to an aluminum base or an anodized aluminum base. The
GDP 133 may be made from Si or SiC, or may be a ceramic such as
Y.sub.2O.sub.3, Al.sub.2O.sub.3, YAG, and so forth.
[0023] For processing chambers used for conductor etch (etching of
conductive materials), a lid may be used rather than a showerhead.
The lid may include a center nozzle that fits into a center hole of
the lid. The lid may be a ceramic such as Al.sub.2O.sub.3,
Y.sub.2O.sub.3, YAG, or a ceramic compound composed of
Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3-ZrO.sub.2. The nozzle may also be a ceramic, such as
Y.sub.2O.sub.3, YAG, or the ceramic compound composed of
Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3-ZrO.sub.2. The lid, base of showerhead 130, GDP 133
and/or nozzle may be coated with a ceramic layer, which may be
composed of one or more of any of the ceramic compositions
described herein. The ceramic layer may be a plasma sprayed layer,
a physical vapor deposition (PVD) deposited layer, an ion assisted
deposition (IAD) deposited layer, or other type of layer. In one
embodiment, the ceramic layer may have been coated onto the chamber
component prior to formation of apertures.
[0024] Examples of processing gases that may be used to process
substrates in the processing chamber 100 include halogen-containing
gases, such as C.sub.2F.sub.6, SF.sub.6, SiCl.sub.4, HBr, NF.sub.3,
CF.sub.4, CHF.sub.3, CH.sub.2F.sub.3, F, NF.sub.3, Cl.sub.2,
CCl.sub.4, BCl.sub.3 and SiF.sub.4, among others, and other gases
such as O.sub.2, or N.sub.2O. Examples of carrier gases include
N.sub.2, He, Ar, and other gases inert to process gases (e.g.,
non-reactive gases). The substrate support assembly 148 is disposed
in the interior volume 106 of the processing chamber 100 below the
showerhead 130 or lid. The substrate support assembly 148 holds the
substrate 144 during processing. A ring 146 (e.g., a single ring)
may cover a portion of the electrostatic chuck 150, and may protect
the covered portion from exposure to plasma during processing. The
ring 146 may be silicon or quartz in one embodiment.
[0025] An inner liner 118 may be coated on the periphery of the
substrate support assembly 148. The inner liner 118 may be a
halogen-containing gas resistant material such as those discussed
with reference to the outer liner 116. In one embodiment, the inner
liner 118 may be fabricated from the same materials of the outer
liner 116. Additionally, the inner liner 118 may be coated with a
ceramic layer and/or have one or more apertures passing
through.
[0026] In one embodiment, the substrate support assembly 148
includes a mounting plate 162 supporting a pedestal 152, and an
electrostatic chuck 150. The electrostatic chuck 150 further
includes a thermally conductive base 164 and an electrostatic puck
166 bonded to the thermally conductive base by a bond 138, which
may be a silicone bond in one embodiment. An upper surface of the
electrostatic puck 166 is covered by the ceramic layer 136 in the
illustrated embodiment. In one embodiment, the ceramic layer 136 is
disposed on the upper surface of the electrostatic puck 166. In
another embodiment, the ceramic layer 136 is disposed on the entire
exposed surface of the electrostatic chuck 150 including the outer
and side periphery of the thermally conductive base 164 and the
electrostatic puck 166. The mounting plate 162 is coupled to the
bottom 110 of the chamber body 102 and includes passages for
routing utilities (e.g., fluids, power lines, sensor leads, etc.)
to the thermally conductive base 164 and the electrostatic puck
166.
[0027] The thermally conductive base 164 and/or electrostatic puck
166 may include one or more optional embedded heating elements 176,
embedded thermal isolators 174 and/or conduits 168, 170 to control
a lateral temperature profile of the substrate support assembly
148. The conduits 168, 170 may be fluidly coupled to a fluid source
172 that circulates a temperature regulating fluid through the
conduits 168, 170. The embedded thermal isolator 174 may be
disposed between the conduits 168, 170 in one embodiment. The
heating element 176 is regulated by a heater power source 178. The
conduits 168, 170 and heating element 176 may be utilized to
control the temperature of the thermally conductive base 164, which
may be used for heating and/or cooling the electrostatic puck 166
and a substrate 144 (e.g., a wafer) being processed. The
temperature of the electrostatic puck 166 and the thermally
conductive base 164 may be monitored using a plurality of
temperature sensors 190, 192, which may be monitored using a
controller 195.
[0028] The electrostatic puck 166 may further include multiple gas
passages or apertures such as grooves, mesas and other surface
features, which may be formed in an upper surface of the
electrostatic puck 166 and/or the ceramic layer 136. The gas
passages may be polished in accordance with embodiments described
herein. The gas passages may be fluidly coupled to a source of a
heat transfer (or backside) gas such as helium via apertures
drilled in the electrostatic puck 166. In operation, the backside
gas may be provided at controlled pressure into the gas passages to
enhance the heat transfer between the electrostatic puck 166 and
the substrate 144. The electrostatic puck 166 includes at least one
clamping electrode 180 controlled by a chucking power source 182.
The clamping electrode 180 (or other electrode disposed in the
electrostatic puck 166 or conductive base 164) may further be
coupled to one or more RF power sources 184, 186 through a matching
circuit 188 for maintaining a plasma formed from process and/or
other gases within the processing chamber 100. The power sources
184, 186 are generally capable of producing an RF signal having a
frequency from about 50 kHz to about 3 GHz, with a power output of
up to about 10,000 Watts.
[0029] FIG. 2 illustrates an exemplary architecture of a
manufacturing system 200 according to one embodiment. The
manufacturing system 200 may be a ceramics manufacturing system,
which may include the processing chamber 100. In some embodiments,
the manufacturing system 200 may be a processing chamber for
manufacturing, cleaning, or modifying a chamber component of the
processing chamber 100. In one embodiment, the manufacturing system
200 includes an abrasive flow system 205, an equipment automation
layer 215, and a computing device 220. In alternative embodiments,
the manufacturing system 200 may include more or fewer components.
For example, the manufacturing system 200 may include only the
abrasive flow system 205, which may be a manual off-line
machine.
[0030] The abrasive flow system 205 may be a machine designed to
direct a flow of an abrasive media through one or more apertures of
an article (e.g., a ceramic article for use in a semiconductor
processing chamber). The abrasive flow system 205 may include a
mounting stage and a clamp used to hold the article in place during
processing, so as to produce a fixture with a sealed flow path for
flowing the abrasive media through the article. The abrasive flow
system 205 may include an external pump for pumping the abrasive
media through the fixture. The clamp may be a pneumatic or
hydraulic clamp, and the abrasive flow system 205 may additionally
include other pumps that are used to generate a clamping force.
[0031] The abrasive flow system 205 may be an off-line machine that
can be programmed with a process recipe. The process recipe may
control the applied clamping force, flow rates, flow directions,
process times, or any other suitable parameter. Alternatively,
abrasive flow system 205 may be an on-line automated machine that
can receive process recipes from computing devices 220 (e.g.,
personal computers, server machines, etc.) via an equipment
automation layer 215. The equipment automation layer 215 may
interconnect the abrasive flow system 205 with computing devices
220, with other manufacturing machines, with metrology tools,
and/or other devices.
[0032] The equipment automation layer 215 may include a network
(e.g., a location area network (LAN)), routers, gateways, servers,
data stores, and so on. The abrasive flow system 205 may connect to
the equipment automation layer 215 via a SEMI Equipment
Communications Standard/Generic Equipment Model (SECS/GEM)
interface, via an Ethernet interface, and/or via other interfaces.
In one embodiment, the equipment automation layer 215 enables
process data (e.g., data collected by the abrasive flow system 205
during a process run) to be stored in a data store (not shown). In
an alternative embodiment, the computing device 220 connects
directly to the abrasive flow system 205.
[0033] In one embodiment, the abrasive flow system 205 includes a
programmable controller that can load, store and execute process
protocols. The programmable controller may pressure settings, fluid
flow settings, time settings, etc. for a process performed by
abrasive flow system 205. The programmable controller may include a
main memory (e.g., read-only memory (ROM), flash memory, dynamic
random access memory (DRAM), static random access memory (SRAM),
etc.), and/or a secondary memory (e.g., a data storage device such
as a disk drive). The main memory and/or secondary memory may store
instructions for performing abrasive flow polishing, as described
herein.
[0034] The programmable controller may also include a processing
device coupled to the main memory and/or secondary memory (e.g.,
via a bus) to execute the instructions. The processing device may
be a general-purpose processing device such as a microprocessor,
central processing unit, or the like. The processing device may
also be a special-purpose processing device, such as an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA), a digital signal processor (DSP), a network processor, or
the like. In one embodiment, programmable controller is a
programmable logic controller (PLC).
[0035] FIG. 3 depicts a sectional view of an abrasive flow system
300 according to an embodiment. For example, the abrasive flow
system 300 may be the same or similar to manufacturing system 200
described with respect to FIG. 2. The abrasive flow system 300 may
be configured to perform abrasive flow polishing on an article 302
(e.g., a ceramic chamber component). A fixture may be formed by
clamping the article 302 between a clamp 318 and a mounting stage
314. A ring 322 may be placed around the article 302, which
contacts the mounting stage 314 and the clamp 318. Each of the
mounting stage 314, the clamp 318, and the ring 322 may be a
metallic material (e.g., stainless steel) or a ceramic material
(e.g., any of the ceramic compositions described herein). In some
embodiments, o-rings are placed between the mounting stage 314 and
the ring 322 and/or the clamp 318 and the ring 322. In some
embodiments, the claim 318 may be a hydraulic clamp or a pneumatic
clamp. The clamp 318 may be capable of applying a clamping pressure
between about 1500 pounds per square-inch (psi) and about 2500 psi
to the article 302.
[0036] The article 302 may be any suitable chamber component
described with respect to FIG. 1, including a substrate support
assembly, an electrostatic chuck (ESC), a chamber wall, a base, a
gas distribution plate or showerhead, a liner, a liner kit, a
shield, a plasma screen, a flow equalizer, a cooling base, a
chamber lid, etc. The article 302 may be a ceramic material,
metal-ceramic composite, or a polymer-ceramic composite. As
illustrated in FIG. 3, the article 302 includes apertures 304 and
310, which pass through the article 302. The apertures 304 and 310
may have any suitable shape, such as circular, c-slot, etc. Other
shapes of the apertures 304 and 310 may also be provided. The
article 302 may have any suitable dimensions for incorporation into
a semiconductor chamber. For example, in some embodiments, the
article 302 may be a showerhead having a thickness between about 50
mm to about 200 mm. The article 302 may also have a diameter of
between about 200 to about 500 mm.
[0037] As depicted in FIG. 3, in one embodiment the aperture 304
includes a first region 306a having a first diameter (e.g., about
0.1 inches) and a second region 306b having a second diameter
(e.g., about 0.05 inches). The aperture 304 is formed by the first
region 306a and second region 306b joined by a junction 308 between
the first region 306a and second region 306b. For example, the
first region 306 may have been formed by drilling a hole into the
article 302 using a first drill, and the second region 306b may
have been formed by drilling a hole into the article 302 using a
second drill with a smaller diameter bit than the first drill.
Aperture 310 may have been formed in a similar manner as aperture
304. For example, aperture 310 has a first region 312a having a
first diameter and a second region 312b having a second diameter.
In some embodiments, for any aperture, a diameter of the aperture
may range from about 0.01 inches to about 0.1 inches. It is noted
that apertures 304 and 310 are merely illustrative, and any
suitable aperture (e.g., with or without bends and with or without
multiple diameters) may be formed in article 302.
[0038] The mounting stage 314 may include multiple apertures
passing through the mounting stage 314, such as central aperture
316a and side apertures 316b. Similarly, the clamp 318 may include
multiple apertures passing through the clamp 318, such as central
aperture 320a and side apertures 320b. The mounting stage 314,
clamp 318, and their respective apertures 316a, 316b, 320a, and
320b may be sized and shaped to interface with the article 302 such
that flow paths 332 and 334 are defined through the mounting stage
314, article 302, and clamp 318 for an abrasive media to pass
through. In some embodiments, one or more of pads 324 and 326 may
be placed, respectively, between the clamp 318 and the article 302
and between the mounting stage 314 and the article 302. Each of
pads 324 and 326 may be multilayered and/or have multiple pads. In
some embodiments, the pads 324 and 326 are rubber pads (e.g.,
urethane, polyoxymethylene, etc.). The pads 324 and 326 may be
fabricated to be of suitable shapes to allow for variance in the
height/dimensions of the article 302. In some embodiments, if less
than all of the apertures of the article are to be polished with
the abrasive media, one or more of the mounting stage 314, the pads
324 and 326, the clamp 318, and the ring 322 may be
fabricated/machined such that the flow path passes through the
apertures that are to be polished while blocking the flowpath
through the one or more apertures that are not to be polished.
[0039] A pump 330 may be coupled to the mounting stage 314 and the
clamp 318. The pump 330 may provide the pressure used to flow the
abrasive media through the apertures 304 and 310 of the article
302. For example, the pump 330 may be an axial piston pump, a
radial piston pump, a hydraulic pump, etc. In one embodiment, the
pressure applied by the pump 330 is between about 500 psi and about
1500 psi. The pump 330 may be configured to repeatedly flow the
abrasive media back and forth through the apertures 304 and 310 for
a duration of time suitable for producing a smooth finish within
the aperture interiors. Accordingly, the pump 330 may flow the
abrasive media through the apertures 304, 310 in a first direction,
and then reverse the flow of the abrasive media and flow it back
through the apertures 304, 310 in the opposite direction. In one
embodiment, the pump may include a piston disposed on either side
of the fixture (e.g., on either side of the mounting stage 314 and
the clamp 318). The abrasive media may be forced through the
apertures 316a, 316b, 304, 310, 320a, and 320b by alternating the
stroke of each piston. The force supplied by each piston, the
frequency of the piston motion, and the total processing time may
be adjusted to polish the interior surfaces of the apertures 304
and 310. In some embodiments, the processing time duration is
between about 5 minutes and about 30 minutes.
[0040] The processing time duration may be pre-determined based on
previously generated surface morphology micrographs used as
guidelines for determining a target finish. In one embodiment, the
target finish time is based on a measured surface roughness. For
example, a protocol (e.g., including parameters such as abrasive
grit, abrasive particle concentration, number of cycles, pressures,
etc.) may be defined by determining a combination of parameters
that yield a particular range of surface roughnesses. In one
embodiment, the processing time duration may be selected such that
a target volume of abrasive media is flowed through the apertures.
Given a flow rate Q (which can be controlled by the pump 330) and a
target volume V, the total processing time t is defined as V/Q. In
some implementations, a flow rate is between about 10 in.sup.3/min
and about 30 in.sup.3/min, and a total processing time is between
about 10 minutes and about 30 minutes.
[0041] In some embodiments, the abrasive media may be a slurry. For
example, the slurry may include abrasive particles dispersed in a
liquid, such as a high viscosity liquid having a polymer base. The
particles may be delivered to the interior of apertures of a
ceramic article in a solution containing water, an oil-based
plasticizer, and/or any other liquid capable of suspending the
particles. In some embodiments, the particles may make up between
about 10 to about 80 percent by weight of the slurry. The viscosity
of the slurry may be adjusted by adjusting either particle
concentration, solution composition, or a combination thereof.
Increased viscosity may result in greater smoothness of the
interior surfaces of the apertures and improved removal of the
damaged surfaces. In some embodiments, the viscosity of the slurry
may be between about 150,000 centiPoise (cP) to about 750,000 cP.
In some embodiments, the particles may comprise at least one of
diamond, silicon carbide (SiC), or boron carbide (BC). In some
embodiments, a mass-median-diameter (D50) of the particles in the
slurry, which is the average particle diameter by mass, may be
between about 1 micrometer and about 100 micrometers. In some
embodiments, a D50 of the particles may be between about 20
micrometers and about 30 micrometers. Smaller grit sizes may cause
the polished surface of the apertures to be smoother. However, in
some instances it takes longer to polish the apertures with smaller
grit sizes. In some instances, a first abrasive media with a first
grit size is used initially followed by a second abrasive media
having a second smaller grit size.
[0042] FIGS. 4a-4i are micrographs comparing unpolished apertures
to apertures polished according to an embodiment. Each of FIGS.
4a-4i show the interior surfaces of a 0.05 inch diameter aperture
within a chamber nozzle. FIGS. 4a-c show different views of the
aperture of the nozzle prior to abrasive flow polishing, in which
cracks and grain boundaries along the interior surface are clearly
visible. FIGS. 4d-f show an interior surface of an aperture after
abrasive flow polishing with 250 in.sup.3 of abrasive media. FIGS.
4g-i show the interior surface of an aperture after abrasive flow
polishing with 500 in.sup.3 of abrasive media, showing an
improvement over FIGS. 4d-f with increasing abrasive media
treatment (a surface roughness less than 25 .mu.in)
[0043] FIG. 5 is a flow diagram illustrating a process 500 for
polishing interior surfaces of apertures in an article according to
an embodiment. At block 502, an article is provided, the article
having at least one aperture and being a component for a
semiconductor processing chamber. In one embodiment, one or more
apertures of the article vary in diameter. For example, a first
portion of the aperture may have a first diameter and a second
portion of the aperture may have a second diameter. The one or more
apertures may also be non-linear (e.g., the aperture may change
directions within the article). An aperture with multiple diameters
and that changes directions poses challenges to conventional
polishing techniques.
[0044] In one embodiment, the article is a semiconductor chamber
component, such as a lid, a nozzle, an electrostatic chuck, a
showerhead, a liner kit, or any other suitable chamber component
having apertures. In one embodiment, the article is a metal article
such as aluminum, an aluminum alloy, titanium, stainless steel, and
so on. In one embodiment, the article is a polymer based material.
In one embodiment, the article includes multiple different
materials (e.g., a metal base and a ceramic layer over the metal
base).
[0045] In one embodiment, the article is a ceramic article. In one
embodiment, the article may be a ceramic article having a
composition that includes one or more of Al.sub.2O.sub.3, AlN,
SiO.sub.2, Y.sub.3Al.sub.5O.sub.12, Y.sub.4Al.sub.2O.sub.9,
Y.sub.2O.sub.3, Er.sub.2O.sub.3, Gd.sub.2O.sub.3,
Er.sub.3Al.sub.5O.sub.12, Gd.sub.3Al.sub.5O.sub.12, YF.sub.3,
Nd.sub.2O.sub.3, Er.sub.4Al.sub.2O.sub.9, ErAlO.sub.3,
Gd.sub.4Al.sub.2O.sub.9, GdAlO.sub.3, Nd.sub.3Al.sub.5O.sub.12,
Nd.sub.4Al.sub.2O.sub.9, NdAlO.sub.3, or a ceramic compound
composed of Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3-ZrO.sub.2. In some embodiments, the article may
alternatively or additionally include ZrO.sub.2, Al.sub.2O.sub.3,
SiO.sub.2, B.sub.2O.sub.3, Nd.sub.2O.sub.3, Nb.sub.2O.sub.5,
CeO.sub.2, Sm.sub.2O.sub.3, Yb.sub.2O.sub.3, or other oxides.
[0046] With reference to the ceramic compound composed of
Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3-ZrO.sub.2, in one embodiment, the ceramic compound
includes 62.93 molar ratio (mol %) Y.sub.2O.sub.3, 23.23 mol %
ZrO.sub.2 and 13.94 mol % Al.sub.2O.sub.3. In another embodiment,
the ceramic compound can include Y.sub.2O.sub.3 in a range of 50-75
mol %, ZrO.sub.2 in a range of 10-30 mol % and Al.sub.2O.sub.3 in a
range of 10-30 mol %. In another embodiment, the ceramic compound
can include Y.sub.2O.sub.3 in a range of 40-100 mol %, ZrO.sub.2 in
a range of 0-60 mol % and Al.sub.2O.sub.3 in a range of 0-10 mol %.
In another embodiment, the ceramic compound can include
Y.sub.2O.sub.3 in a range of 40-60 mol %, ZrO.sub.2 in a range of
30-50 mol % and Al.sub.2O.sub.3 in a range of 10-20 mol %. In
another embodiment, the ceramic compound can include Y.sub.2O.sub.3
in a range of 40-50 mol %, ZrO.sub.2 in a range of 20-40 mol % and
Al.sub.2O.sub.3 in a range of 20-40 mol %. In another embodiment,
the ceramic compound can include Y.sub.2O.sub.3 in a range of 70-90
mol %, ZrO.sub.2 in a range of 0-20 mol % and Al.sub.2O.sub.3 in a
range of 10-20 mol %. In another embodiment, the ceramic compound
can include Y.sub.2O.sub.3 in a range of 60-80 mol %, ZrO.sub.2 in
a range of 0-10 mol % and Al.sub.2O.sub.3 in a range of 20-40 mol
%. In another embodiment, the ceramic compound can include
Y.sub.2O.sub.3 in a range of 40-60 mol %, ZrO.sub.2 in a range of
0-20 mol % and Al.sub.2O.sub.3 in a range of 30-40 mol %. In
another embodiment, the ceramic compound can include Y.sub.2O.sub.3
in a range of 30-60 mol %, ZrO.sub.2 in a range of 0-20 mol % and
Al.sub.2O.sub.3 in a range of 30-60 mol %. In another embodiment,
the ceramic compound can include Y.sub.2O.sub.3 in a range of 20-40
mol %, ZrO.sub.2 in a range of 20-80 mol % and Al.sub.2O.sub.3 in a
range of 0-60 mol %. In other embodiments, other distributions may
also be used for the ceramic compound.
[0047] In one embodiment, an alternative ceramic compound that
includes a combination of Y.sub.2O.sub.3, ZrO.sub.2,
Er.sub.2O.sub.3, Gd.sub.2O.sub.3 and SiO.sub.2 is used for the
article. In one embodiment, the alternative ceramic compound can
include Y.sub.2O.sub.3 in a range of 40-45 mol %, ZrO.sub.2 in a
range of 0-10 mol %, Er.sub.2O.sub.3 in a range of 35-40 mol %,
Gd.sub.2O.sub.3 in a range of 5-10 mol % and SiO2 in a range of
5-15 mol %. In another embodiment, the alternative ceramic compound
can include Y.sub.2O.sub.3 in a range of 30-60 mol %, ZrO.sub.2 in
a range of 0-20 mol %, Er.sub.2O.sub.3 in a range of 20-50 mol %,
Gd.sub.2O.sub.3 in a range of 0-10 mol % and SiO2 in a range of
0-30 mol %. In a first example, the alternative ceramic compound
includes 40 mol % Y.sub.2O.sub.3, 5 mol % ZrO.sub.2, 35 mol %
Er.sub.2O.sub.3, 5 mol % Gd.sub.2O.sub.3 and 15 mol % SiO.sub.2. In
a second example, the alternative ceramic compound includes 45 mol
% Y.sub.2O.sub.3, 5 mol % ZrO.sub.2, 35 mol % Er.sub.2O.sub.3, 10
mol % Gd.sub.2O.sub.3 and 5 mol % SiO.sub.2. In a third example,
the alternative ceramic compound includes 40 mol % Y.sub.2O.sub.3,
5 mol % ZrO.sub.2, 40 mol % Er.sub.2O.sub.3, 7 mol %
Gd.sub.2O.sub.3 and 8 mol % SiO.sub.2. In one embodiment, the
article includes 70-75 mol % Y.sub.2O.sub.3 and 25-30 mol %
ZrO.sub.2. In a further embodiment, the article is a material
entitled YZ20 that includes 73.13 mol % Y.sub.2O.sub.3 and 26.87
mol % ZrO.sub.2.
[0048] Referring back to FIG. 5, at block 504, the at least one
aperture of the article is polished based on flowing an abrasive
media through the at least one aperture of the article. The
abrasive media includes a polymer base and multiple abrasive
particles suspended in the polymer base. The abrasive media may
polish the apertures even if the apertures vary in diameter and are
non-linear. In one embodiment, the abrasive particles include at
least one of silicon carbide, diamond, or boron nitride. An average
size of the abrasive particles may range from 5 micrometers to 100
micrometers. In one embodiment, the article is polished using an
abrasive flow system (e.g., abrasive flow system 300), which is
described in more detail below with respect to FIG. 6.
[0049] FIG. 6 is a flow diagram illustrating a process 600 for
polishing interior surfaces of apertures in a ceramic article
according to another embodiment. At block 602, a ceramic article is
provided. The ceramic article may by any suitable ceramic article
described herein, such as a component of a semiconductor processing
chamber. The ceramic article may include one or more of the ceramic
materials described with respect to block 502 of FIG. 5.
[0050] At block 604, holes are drilled through the ceramic article
to produce at least one aperture. In one embodiment, each aperture
may be of a size range from about 0.01 inches to about 0.1 inches.
In one embodiment, a first hole having a first diameter (e.g.,
between about 0.05 inches and 0.1 inches) is drilled into or
through the ceramic article, and a second hole having a second
diameter (e.g., between about 0.01 inches and about 0.05 inches) is
drilled into the ceramic article (e.g., through the first hole, or
into a different portion of the ceramic article). The first and
second holes may intersect, forming an aperture through the ceramic
article that has a first diameter at a first region (corresponding
to the first hole) and a second diameter at a second region
(corresponding to the second hole). In one embodiment, the first
diameter is greater than the second diameter. In one embodiment,
the first region is parallel with the second region (e.g., a linear
aperture having two different diameters at different portions). In
one embodiment, the aperture has a bend (e.g, the first region and
second region intersect, but are not parallel).
[0051] In one embodiment, at block 606, the at least one aperture
is reamed with a reaming device to increase a diameter of the at
least one aperture. The diameter of the reaming device may be
selected to be larger than a diameter of the at least one aperture
(e.g., by about 0.5% to about 2% larger that the diameter of the at
least one aperture). In one embodiment, the drill may have a first
grit size, and the ream may have a second grit size, and the first
grit size of the drill is courser than the second grit size of the
ream. In one embodiment, the first grit size of the drill is
between about 100 grit and about 150 grit. In one embodiment, the
second grit size of the reaming device is between about 400 grit
(e.g., about 40 micrometer particle size) and 800 grit (e.g., about
25 micrometer particle size).
[0052] At block 608, the ceramic article is clamped within an
abrasive flow system (e.g., abrasive flow system 300 of FIG. 3).
The abrasive flow system may include a mounting stage (e.g.,
mounting stage 314) and a clamp (e.g., clamp 318). The ceramic
article may be placed between the clamp and the mounting stage such
that a flow path for an abrasive media is defined by the at least
one aperture, such that the abrasive media may flow from the
mounting stage, through the at least one aperture, and through the
clamp (as illustrated in FIG. 3). In some embodiments, the clamp
may be a hydraulic clamp or a pneumatic clamp. In some embodiments,
the clamp may apply a clamping pressure to the ceramic article that
is between about 1,500 psi and 2,500 psi. In some embodiments, one
or more pads (e.g., pads 326 and 324) are disposed between the
ceramic article and the clamp, and/or the ceramic article and the
mounting stage.
[0053] At block 610, the at least one aperture is polished by
pumping the abrasive media through the at least one aperture using
the abrasive flow system. A pump (e.g., pump 330) may be fluidly
coupled to the abrasive flow system such that the abrasive media
flows through the at least one aperture of the ceramic article. In
one embodiment, the pump provides a pressure of about 500 psi to
about 1000 psi to the abrasive media. In one embodiment, the
abrasive media includes many abrasive particles (e.g., thousands or
tens of thousands of abrasive particles). The abrasive particles
may include at least one or silicon carbide, diamond, or boron
nitride particles. In one embodiment, the average size of each of
the plurality of abrasive particles ranges from 5 to 100
micrometers.
[0054] At block 612, a flow direction of the abrasive media through
the at least one aperture is periodically adjusted over a time
duration. In one embodiment, the time duration is between about 20
minutes and about 60 minutes. In one embodiment, the flow direction
may be changed (e.g., from a forward direction to a reverse
direction) one or more times during the time duration. For example,
the flow direction may be changed every 5-10 minutes. In one
embodiment, the abrasive media includes an oil-based plasticizer.
In one embodiment, a viscosity of the abrasive media is between
about 150,000 cP and about 750,000 cP.
[0055] After flowing the abrasive media through the at least one
aperture, the at least one aperture may have a surface roughness
(average surface roughness, Ra) of less than 32 .mu.in. In one
embodiment, an opening of the at least one aperture (at an outer
surface of the ceramic article) has a rounded edge after the
polishing.
[0056] In one embodiment, a ceramic plasma resistant layer is
formed on the article after the apertures are polished. The ceramic
plasma resistant layer may be composed of any of the aforementioned
ceramics, and may be deposited onto the article by plasma spraying,
physical vapor deposition, ion assisted deposition, or other
deposition techniques. In an alternative embodiment, the ceramic
plasma resistant layer may be formed on a surface of the article
before the holes are drilled and the polishing is performed.
[0057] The preceding description sets forth numerous specific
details such as examples of specific systems, components, methods,
and so forth, in order to provide a good understanding of several
embodiments of the present invention. It will be apparent to one
skilled in the art, however, that at least some embodiments of the
present invention may be practiced without these specific details.
In other instances, well-known components or methods are not
described in detail or are presented in simple block diagram format
in order to avoid unnecessarily obscuring the present invention.
Thus, the specific details set forth are merely exemplary.
Particular embodiments may vary from these exemplary details and
still be contemplated to be within the scope of the present
disclosure.
[0058] Reference throughout this specification to "one embodiment"
or "an embodiment" indicates that a particular feature, structure,
or characteristic described in connection with the embodiment is
included in at least one embodiment. Thus, the appearances of the
phrase "in one embodiment" or "in an embodiment" in various places
throughout this specification are not necessarily all referring to
the same embodiment. In addition, the term "or" is intended to mean
an inclusive "or" rather than an exclusive "or." When the term
"about" or "approximately" is used herein, this is intended to mean
that the nominal value presented is precise within .+-.10%.
[0059] Although the operations of the methods herein are shown and
described in a particular order, the order of the operations of
each method may be altered so that certain operations may be
performed in an inverse order or so that certain operation may be
performed, at least in part, concurrently with other operations. In
another embodiment, instructions or sub-operations of distinct
operations may be in an intermittent and/or alternating manner.
[0060] It is to be understood that the above description is
intended to be illustrative, and not restrictive. Many other
embodiments will be apparent to those of skill in the art upon
reading and understanding the above description. The scope of
embodiments of the invention should, therefore, be determined with
reference to the appended claims, along with the full scope of
equivalents to which such claims are entitled.
* * * * *